The instant invention relates to a drive unit which can be used to drive sheet conveyors in a sheet reading apparatus, for example, a banknote reader.
A drive unit for a vending machine having a banknote reader is known from U.S. Pat. No. 4,011,931. A conveyor belt conveys a banknote from a testing device, which recognizes characteristics of the banknote, either into a device for the stacking of banknotes or, when it is rejected, into a return compartment. The conveyor belt and the banknote stacking device are driven by two independently controlled motors.
The publication Research Disclosure 24820 of Dec. 10, 1984, describes a stacking drive operated by means of a crank shaft which, in contrast to the apparatus of U.S. Pat. No. 4,011,931, requires no reversal of the direction of rotation of the drive motor for stacking.
Banknote readers may be provided with an intermediary cash box as an additional feature, as is known from DE PS 26 19 620, for example. In such banknote readers, the direction of banknote transport must be reversed for the intermediate storing of banknotes.
Furthermore, testing devices to recognize optical and/or magnetic characteristics on sheets or banknotes are also known. See, e.g., the color recognition system described in CH-PS 573 634.
It is an object of the instant invention to provide a low-cost drive unit for a banknote reader which produces high torque and enables rapid intake of banknotes.